将对象数组映射到Int数组

Question

I'm trying to map and filter my Object[] array to int[] array. Works great, if an object is an int, but throws cast exception if not. I'm wondering if I can somehow attach an try/catch in lambda expression? Here's my code:

b[i] = Arrays.stream(item).mapToInt(e -> (int) e).filter(e -> e % 2 != 0).toArray();

or better way is just to try/catch whole block?

Answer 1

Wy不过滤整数对象？

.filter(i -> i instanceof Integer).mapToInt(e -> (int) e)

Answer 2

Use filter() to remove non-numerical values, then convert to Number and call the intValue() method.

int[] ints = Arrays.stream(objects)
    .filter(Number.class::isInstance)
    .map(Number.class::cast)
    .mapToInt(Number::intValue)
    .toArray();